. ~ COMMON SWIFT, — 295 
the garden-walk it instantly took wing; whilst on another occasion one 
was placed on the floor of a room, but took flight at once and flew against 
the window. Naumann had previously recorded a similar experiment. 
Swifts often chase each other in the pairing-season, and harmless 
combats between rival males are sometimes noticed. The Swift most 
probably pairs for life. Every year the old familiar hole is tenanted 
presumably by the same pair of birds; and Gilbert White long ago 
noticed how regularly the same number of Swifts frequented certain 
haunts for years. The Swift does not tarry long after its arrival in this 
country before nesting-duties are commenced. It is a late bird to come; 
its stay is short, therefore no time can be wasted. The scanty nest is 
usually commenced by the middle of May; eggs are laid by the end of 
the month; and the young are usually hatched by the middle of June. 
The nest is built either in the crevice of a wall, a hole in a rock, or, where 
there are no rocks, ina mud cliff or tower, or under the roofs of buildings, 
in a similar situation to that so often chosen by House-Sparrows. When 
the Swift builds in the latter situations, it is probably because a loftier 
site cannot be had, for the bird likes to build in as elevated a position as 
it can find. It is also said to occasionally nest in a crevice in the face of 
a chalk-pit. It breeds regularly in the limestone cliffs facing the sea at 
Llandudno and elsewhere ; and it sometimes builds in the hollow branches 
of old and decayed oaks. 
The nest of the Swift is a very slight structure, almost flat, composed 
of bits of straw and other vegetable fibres, placed together with very little 
art, and lined with feathers; these materials are covered with a viscid 
saliva which solidifies like glue, and renders the nest hard and caked 
together. The Swift obtains most of the materials with which it builds 
its nest whilst on the wing, seizing a feather here or a bit of dry grass 
there, as they may happen to be blown into the air. It also finds hay, 
straw, &c. under the tiles and in the crevices which it frequents, conveyed 
thither by Sparrows; indeed the nest has even been found on a nest of 
this bird containing eggs! the Swift having, doubtless, ejected the usurp- 
ing tenant. The eggs of the Swift are two or three in number, generally 
the former, but sometimes as many as four are laid. They are elongated 
in shape, the small end almost as blunt as the large end, rough in texture, 
with little gloss, and almost pure white in colour. They vary from 1-08 
to ‘98 inch in length, and from ‘7 to ‘62 inch in breadth. Swifts’ eggs 
are readily distinguished from those of the Martin by their larger size, 
more oval shape, and rougher texture ; from those of the White-bellied 
Swift, the species next to be described, their smaller size distinguishes 
them at once. The female alone apparently performs the duties of in- 
cubation, and the male often conveys food to her. According to Gilbert 
White, whose account of this bird is very complete, she only leaves her 
